Double-pole slide switch

ABSTRACT

Double-pole slide switch of the type having a switch slide, a housing and pivotally supported contact elements which are snapaction-fashion reversible by operation of the switch slide, said switch having double-armed contact elements pivotally supported in stationary connecting elements, a first arm of each contact element cooperating with stationary counter-contacts and a second arm of each contact element engaging a recess of the switch slide, there being provided a compression spring between a potshaped middle portion of the slide and a stationary part of the switch housing, said spring constituting a power storage for the snap-action operation of a switch.

United States Patent Inventor RudolfHinkelmann Bad Neustadt, Germany Appl. No 6,149 Filed Jan. 27, I970 Patented Oct. 12, 1971 Assignee PREH Electro-Feinmechanische Werke,

Jakob Preh Nachi Bad Neustadt/Saale, Germany Priority Feb. 28, 1969 Germany P 19 10 165.6

DOUBLE-POLE SLIDE SWITCH 7 Claims, 3 Drawing Figs.

US. Cl 200/67 A, 200/76 Int. Cl H0lh 13/28 Field of Search 200/67 A, 67 D, 76, 67 R Primary Examiner-David Smith, Jr. Attorney-Stowe]! & Stowell ABSTRACT: Double-pole slide switch of the type having a switch slide, a housing and pivotally supported contact elements which are snap-action-fashion reversible by operation of the switch slide, said switch having double-armed contact elements pivotally supported in stationary connecting elements, a first arm of each contact element cooperating with stationary counter-contacts and a second arm of each contact element engaging a recess of the switch slide, there being provided a compression spring between a pot-shaped middle portion of the slide and a stationary part of the switch housing, said spring constituting a power storage for the snap-action operation of a switch.

PATENTEDUCT 12 I97! 3 6 1 2 7 92 Inventor"- DOUBLE-POLE SLIDE SWITCH invention relate to a double-pole slide switch having pivotally supported contact elements the double-pole of which are reversible snap-action fashion by operation of the switch slide. Such switches are used on a large scale as main switches in electronic apparatus, often in connection with other elements such as for instance wave-range switches or volume controls in broadcasting receivers.

Double-pole slide switches are already known, such as by the West-German Utility Model 1 913 691, in which the movable contact elements are formed as switch rocker arms having lateral recesses, into which coil springs are inserted, these springs engaging by their one ends in the switch rocker arms and by their other ends on pins of the switch slide which is arranged approximately perpendicular to the switch rocker arms. Moreover, it is known, for instance from West-German Utility Model 1 928 070 to support in such a switch the switch slide on a pivotally reversible element which is rotatably fastened on the switch housing and engages by an edge a matchingly shape notch of the slide.

Such switches are relatively simple in their design, although there are limits in regard to their reduction in size on account of the necessary safety distances and on account of the minimal stroke required for the safety of switching, so that they are not well suited for the very close space conditions in miniaturized appliances.

The object of the invention to design a slide switch of the above-indicated type, which has very small outer dimensions and a very short stroke of the slide, very high reliability and a long life and in which the prescribed safety distances between the current conducting metal parts are maintained.

The aforesaid in other objects of the invention are achieved in accordance with the present invention by the provision of a double-pole slide switch, comprising:

a housing having a first sidewall and a second sidewall, said sidewalls being spaced from and facing each other;

a switch slide reciprocably guided within said housing;

a pair of contact elements in the form of two-armed levers, each of said levers having a first arm and a second arm;

each one of said first arms providing a movable contact;

a pair of stationary contacts held in said housing adjacent the said first side wall thereof and each being adapted to cooperate with one of said movable contacts;

said switch slide providing a pair of recesses;

said second arm of each one of said contact elements engaging said slide in one of said recesses;

a pot-shaped formation on said slide facing in a direction opposite to said recesses and having a bottom wall;

a compression spring inserted between said bottom wall and the said second sidewall of said housing;and

means on said slide adapted to be engaged by operating means for reciprocably moving said slide so as to pivot said contact elements.

The switch designed in accordance with the present invention results in a number of advantages. The formation of the movable contact elements as a double-armed lever enables a considerable shortening of the stroke of the slide. The employment of a single spring element as power storage for the snapaction operation and for the provision of the contact pressure leads not only to a reduction of costs but also to a saving of space allowing a reduction of the size of the housing.

A slide has, on account of it three-point support, nowhere area contact so that the friction forces, which could impair the snap-action reversal of the contact elements, are reduced to a minimum. The movement of the slide takes place as parallel slide on a circle section so that the spring in the dead-center position is additionally tensioned and so that thereby tilting moment of the snap-action system is increased.

The location of the metal compression spring in a potshaped middle portion of the slide, consisting of insulating material, allows a very close arrangement of the current-conducting metal parts since the compression spring cannot bridge the air spaces between the same.

The invention and its details as well as further features, objects and advantages thereof will become more easily understood from the embodiment shown as an example in the attached drawing and described in the following. ln the drawings:

FIG. 1 shows a perspective illustration of the switch, wherein the forward half of the housing is indicated phantom like by dot-and-dash lines and in which the switch slide is partly broken away;

FlG. 2 is a plane view of one of the moveable contact elements; and

FIG. 3 is a plan view of a connecting element for a moveable contact elements as shown in FIG. 2.

The switch illustrated in the attached drawing comprises an approximately brick-shaped housing of plastics, the two halves 1 and 2 of which are connected with one another by thermoplastic deformation of pin 3 within the hole 4- of housing half 1. Stationary counter contacts 7 and 8 provided with soldering connections are inserted in slots 5 and 6 of the upper sidewalls of the housing. Approximately in the middle plane of the switch there are provided connecting elements 9 and 10 for pivotally supporting moveable contact elements 11 and 12. These contact elements 9, 10 are inserted in matching grooves of the housing walls. The contact elements 11 and 12 are provided with shoulder surfaces l3, 14 which are pivotally supported in dovetail recesses 9' or 10', respectively, of the connecting elements 9 and 10. The first arms l5, 16' of the moveable contact elements are provided with noble-metal contacts 17, 18 which engage, in the illustrated switched-on condition, under prestress the counter contacts 7, 8.

The second (lower) arms 19, 20 of the moveable contact elements engage V-shaped recesses 21, 22 of switch slide 23. [n the middle between these recesses, the switch slide 23 is provided with a potlike enlargement 24 in the shape of a hollow frustum of a cone. Between the bottom 24' and a shallow recess 25 in the lower side wall of the switch housing there is inserted a precompressed coil spring 26.

The switch slide 23 extends through an opening 27 in the housing with its free end to the outside. This free end is provided with a recess 29 engaged by an operating element 28, the latter being shown in dot-and-dash lines. Connecting tongues 30, 31 are formed on housing half 1.

ln the illustrated switched-on position, the coil spring 26 is inclined to the right from its stationary supporting point 25 and exerts a force on the slide 23, the component of which, extends which is directed perpendicular to the slide, presses the shoulder-surfaces l3, 14 against the connecting elements 9, l0 and thereby produces the necessary contact pressure at these contact locations of the current conducting parts. The force component, which is exerted in the direction of the iongitudinal axis of the slide, is transferred by the double-armed lever to the contact rivets l7, 18 which now on their part engage the counter contacts 7, 8 under a corresponding contact pressure.

For changing of the switching condition, the switch slide 23 is drawn in the direction of the arrow toward the left. The contact elements 11, 12 engaging the recesses 21, 22 perform now a pivotal movement in their supporting points 9', 10 by which the contacts 17, 18 are lifted off the counter contacts 7, 8. Simultaneously, the switch slide 23 performs a parallel sliding movement on a sector of a circle, the radius of which corresponds to the length of the arms 19 and 20. in doing so, the upper end of the coil spring 26 is carried along by the bottom 24', of the potshaped part and the spring 26 is compressed on account of the shortening of the distance between its attachment points. Upon passing the dead-center position, the direction of the power component acting in the longitudinal direction of the slide is reversed to the now a jumplike further movement of the slide is accelerated by the spring in the same direction up to the limit position, i.e. the switched-off position," is reached.

The same operation takes place in the opposite direction upon switching-on, wherein the contacts 7-17 and 848 are closed snap-action fashion.

Slots 5', 6 are besides moreover provided in the housing walls in which the counter contacts 7, 8 may be inserted if the switch should function in the reverse direction, that is if the contacts should be closed when switch slide is pulled out. The switch may also be designed as double-pole reversible switch when all four slots 5, 5', 6, 6' are provided with counter contacts.

Although one preferred embodiment of the invention has been shown and described, modifications and adaptations will present themselves to those skilled in the art without departing from the spirit and the scope of the invention as it is outlined in the attached claims.

What is claimed is:

1. In a double-pole slide switch:

a housing having first and second sidewalls, said sidewalls being spaced from and facing each other;

a switch slide reciprocably guided within said housing;

a pair of electrical contact elements in the form of levers,

each of said levers being pivotally supported in said housing midway of their ends;

the upper portion of said arms each defining a moveable contact;

a pair of stationary contacts held in said housing adjacent one of said sidewalls and each being adapted to be engaged by the upper ends of said pivoted contact elements;

the lower ends of said pivoted contact elements received by recesses in said reciprocating switch slide;

a third recess provided on said slide and facing the bottom wall of the housing;

a compression spring inserted between the bottom wall of the housing and the third recess and extending into the third recess.

2. The switch according to claim 1 wherein:

a pair of connecting elements having portions extending out of said housing defines the pivotal supports for the said levers.

3. The switch according to claim 1 wherein:

said stationary contacts are supported in and extend out of said housing.

4. The switch according to claim 2 wherein:

each of said connecting elements carries a T-slot which receives one of said pivoted contact elements, said pivoted contact elements being formed with a shoulder abutting on side of the respective connecting element adjacent said slot.

5. The switch according to claim 1 wherein:

said compression spring is a helical spring.

6. The switch of claim 1 wherein:

said slide carries means for engagement with an operating mechanism for reciprocably moving the slide.

7. The switch of claim 5 wherein:

the bottom of the housing is provided with a recess into which the spring end, opposite that which extends into said third recess, extends. 

1. In a double-pole slide switch: a housing having first and second sidewalls, said sidewalls being spaced from and facing each other; a switch slide reciprocably guided within said housing; a pair of electrical contact elements in the form of levers, each of said levers being pivotally supported in said housing midway of their ends; the upper portion of said arms each defining a moveable contact; a pair of stationary contacts held in said housing adjacent one of said sidewalls and each being adapted to be engaged by the upper ends of said pivoted contact elements; the lower ends of said pivoted contact elements received by recesses in said reciprocating switch slide; a third recess provided on said slide and facing the bottom wall of the housing; a compression spring inserted between the bottom wall of the housing and the third recess and extending into the third recess.
 2. The switch according to claim 1 wherein: a pair of connecting elements having portions extending out of said housing defines the pivotal supports for the said levers.
 3. The switch according to claim 1 wherein: said stationary contacts are supported in and extend out of said housing.
 4. The switch according to claim 2 wherein: each of said connecting elements carries a T-slot which receives one of said pivoted contact elements, said pivoted contact elements being formed with a shoulder abutting on side of the respective connecting element adjacent said slot.
 5. The switch according to claim 1 wherein: said compression spring is a helical spring.
 6. The switch of claim 1 wherein: said slide carries means for engagemeNt with an operating mechanism for reciprocably moving the slide.
 7. The switch of claim 5 wherein: the bottom of the housing is provided with a recess into which the spring end, opposite that which extends into said third recess, extends. 